Peyton Manning[1]’s NFL[2] future looks tenuous, at best. It was bad enough when we thought he had three neck surgeries, but Wednesday’s report about a fourth unreported operation put the Indianapolis Colts[3] quarterback’s prospects in even more dire straits.

According to Don Banks of Sports Illustrated[4], Manning’s secret neck surgery took place between May 23 and Sept. 9 of last year. The report also says the team believes he will have more operations.

In addition, league sources say Manning’s neck has potentially developed bone spurs just above the point where his latest fusion surgery took place in early September, and the Colts organization is under the belief that it is nearly inevitable Manning will at some point require further surgery, and possibly another fusion procedure, even if he does successfully return to the field in 2012. It’s unclear how any potential long-term neck issues will impact Manning’s decision to attempt a resumption of his NFL playing career later this year.

No player will work harder than Manning to get back on the field, but sometimes the mind is willing, and the body just isn’t able to do anything anymore.

His neck is making it impossible to do the things he has to in order to be a successful NFL quarterback. He doesn’t have arm strength, can’t throw the ball down the field and will probably always have issues throwing to his left.

There are going to be all sorts of rumors and speculation about teams being interested in him over the next few months because of the Manning name, but when you look at his inability to throw the ball and the uncertainty surrounding his neck, there is little hope that he can keep playing quarterback.

Someone like Manning, who has to be in control of everything, doesn’t want to be told when his time is up. That is why he was fighting to get on the field last year, and why he will do anything he can to play next season.

However, the end is here for the future Hall of Fame quarterback. It’s admirable he wants to play for the love of the game. It’s unrealistic to expect him to be able to.

Manning will find that out the hard way if/when the Colts release him and he has to look for work on the free-agent market. Instead of bowing out graciously, he is going to be forced out of the league because his neck won’t let him play anymore.